pandas-dev/pandas · error · ValueError

You must specify at least 4 characters when resetting multip

Error message

You must specify at least 4 characters when resetting multiple keys, use the special keyword "all" to reset all the options to their default value

What it means

Raised by reset_option (config.py:391-396) as a ValueError when the pattern matches multiple keys, is shorter than 4 characters, and is not the reserved 'all'. This guard prevents accidentally resetting a huge swath of options via an overly short prefix like 'di'.

Source

Thrown at pandas/_config/config.py:392

    set_option : Set the value of the specified option or options.
    describe_option : Print the description for one or more registered options.

    Notes
    -----
    For all available options, please view the
    :ref:`User Guide <options.available>`.

    Examples
    --------
    >>> pd.reset_option("display.max_columns")  # doctest: +SKIP
    """
    keys = _select_options(pat)

    if len(keys) == 0:
        raise OptionError(f"No such keys(s) for {pat=}")

    if len(keys) > 1 and len(pat) < 4 and pat != "all":
        raise ValueError(
            "You must specify at least 4 characters when "
            "resetting multiple keys, use the special keyword "
            '"all" to reset all the options to their default value'
        )

    for k in keys:
        set_option(k, _registered_options[k].defval)


def get_default_val(pat: str) -> Any:
    key = _get_single_key(pat)
    opt = _get_registered_option(key)
    assert opt is not None
    return opt.defval


class DictWrapper:
    """provide attribute-style access to a nested dict"""

View on GitHub (pinned to 71959b8cb9)

Solutions

1. Use a longer, unambiguous pattern (>=4 chars), e.g. pd.reset_option('display').
2. Use the fully-qualified key to reset a single option.
3. Use pd.reset_option('all') if you genuinely want to reset every option.

Example fix

# before
pd.reset_option('di')  # ValueError: You must specify at least 4 characters...

# after
pd.reset_option('display')

def safe_reset(pat: str) -> None:
    import pandas._config.config as cf
    keys = cf._select_options(pat)
    if len(keys) > 1 and len(pat) < 4 and pat != 'all':
        raise ValueError(f'Pattern {pat!r} too short; use a longer prefix or "all"')
    pd.reset_option(pat)

try:
    pd.reset_option(pat)
except ValueError as e:
    if 'at least 4 characters' in str(e):
        pd.reset_option('all')  # or pick a longer prefix

When it happens

Trigger: pd.reset_option('di') or pd.reset_option('mode') where several keys match and the pattern is under 4 chars.

Common situations: Trying to batch-reset a namespace using a short prefix without realizing how broad the match is.

Related errors

• No such keys(s): {pat!r}
• Pattern matched multiple keys
• Must provide an even number of non-keyword arguments
• No such keys(s) for {pat=}
• You can only set the value of existing options

AI-assisted analysis of pandas-dev/pandas@71959b8cb9 (2026-08-07). Data as JSON: /api/errors/6df38e80972c6d19. Report an issue: GitHub.